Most of the plants were put in more than ten years ago, the area hasn't been used for anything for a very long time. You can see a concrete retaining wall in the exhibit (on the right) - this wall is about half way into the exhibit, so it has a reasonable depth.
The only thing I'd be concerned about, though, is the horizontal cables. I think if a Casso ran at them full pelt, they might just end up going through.
